Milwaukee MA 957 CO2 Regulator Instuctions

We often read that folks need help hooking up their Milwaukee regulators. Here are some instructions.

Operating Instructions for the Milwaukee MA957

BEFORE YOU START! :

Secure cylinders so that they will not tip or fall.

Inspect the cylinder valves for damaged threads, dirt, oil, or grease. Remove dust and dirt with a clean cloth.

Crack open the cylinder valve for an instant to blow out any foreign matter in the throat of the cylinder.

ATTACHING THE REGULATOR:

Attach the regulator to the cylinder valve placing the supplied plastic o-ring (not shown) between the regulator and the tank. Tighten with a wrench. Omission of this o-ring will cause loss of gas!

Unscrew the large brass ring (G) from the Bubble Counter (H) and fill the bubble counter 1/2 full of fresh water. Be sure the needle valve (B) is closed before filling with water. Once filled, replace the brass o-ring (G).

Before opening the cylinder valve turn the regulator adjustment knob (E) counter clockwise until tension is no longer felt on the knob. Do not fully remove the regulator flow adjustment knob. IF THE CYLINDER VALVE IS OPENED WITH THE REGULATOR KNOB CLOSED, DAMAGE TO THE REGULATOR CAN RESULT!

VERY SLOWLY and CAREFULLY openthe cylinder valve COMPLETELY to seal the cylinder valve packing. The amount of gas in the cylinder can now be read on the High Pressure Gauge (D).

Plug the solenoid (C) into a suitable, grounded, AC Wall outlet, Hanna pH Mini Controller, or Milwaukee SMS122 pH Controller. The solenoid uses slightly more then 6 watts and it is normal for it to feel warm during operation.

Open the needle valve (B) by turning counter-clockwise.

Turn the adjustment knob (E) clockwise until you get a reading on the Low Pressure Gauge (F) of approximately 10lbs on the outside set of numbers (use the numbers on the top row). You should now see bubbles in the counter.

Unplug the Solenoid (C) from the wall or controller and unscrew the compression fitting and pass the air hose through the fitting and attach the tubing to the nipple (A). Be sure your tubing fits tightly on the nipple and that it is pressed all the way down. Slide the compression fitting onto the nipple and tighten.

Plug the Solenoid (C) back into the wall outlet or pH Controller unit and adjust the bubble count on your reactor using the needle valve (B). Fine tuning the count can be accomplished with either the needle valve (B) and by adjusting the regulator output pressure with adjustment knob (E) as discussed in the pevious step. The more you increase the pressure as indicated on the low pressure gauge (F) the more difficult it will be to fine tune your bubble count using needle valve (B). Therefore it is more desirable to keep the pressure indicated on the low pressure gauge (F) low and adjust your bubble count using the Needle Valve (B).

A board member was having trouble maintaining the working pressure on their MA957 Regulator. This was the response from Milwaukee's Technical support:

Trouble Shooting MA957 Regulator

The procedure is as follows:

If you have a pH controller, unplug the solenoid from the controller and Plug your solenoid into a wall socket or power strip. Do not have it plugged into any type of controller or timer to do this adjustment.

Turn your CO2 bottle off. Go to the regulator and turn the main knob counterclockwise till you feel no pressure. Next go to the needle valve that is underneath the bubble counter and turn it counterclockwise all the way out.

Now go back to your CO2 tank and turn the tank to full open. At this point, even with the tank full open you should have no bubbles coming through the bubble counter.

Very slowly, turn the big knob on your regulator in until you start seeing some bubbles come out of your regulator bubble counter. Do not pay any attention to the right side gauge. All we are interested in is the bubble counter.

You must proceed very slowly when trying to adjust the CO2 regulator. Go slow, slow, slow; take your time, we want to slowly work the bubble count up.

Turn the knob one eight to one quarter turn and wait about 30 to 45 seconds or longer before making any further adjustments. Continue with this process until you get a bubble count that is equal to or a little greater than what you're looking for. At a bubble count of 60 bubbles per minute, you might want to take it up to 80 bubbles per minute and then use the needle valve to crank it back down

The right side gauge is not relevant to adjusting your gas flow. Indeed, we have been trying for several months to get them to take the right side gauge off of the regulator because the bubble counter is your true an accurate gauge. Therefore, any reference to the right side gauge serves no purpose.

This procedure, when followed, works about 90% of the time in getting regulators consistent in their flow. The primary problem for poor flow consistency is that too much gas is backed up behind the needle valve causing the diaphragm in the regulator not to function properly.

If you're using a pH controller plug your solenoid back into the pH controller box at this time.

I just set up my Milwaukee regulator and was having problems adjusting it so that any bubbles would consistently enter the bubble counter. Thankfully, more than seven years later, this thread remains. I was able to solve the problem and my regulator is working fine now.

I just set up my Milwaukee regulator and was having problems adjusting it so that any bubbles would consistently enter the bubble counter.

Having this issue right now. Does any one have any more input? I tried the trouble shoot and was getting one bubble per 30-45 seconds. This regulator is only a week old. Did I ruin it already or are these cheap?

Having this issue right now. Does any one have any more input? I tried the trouble shoot and was getting one bubble per 30-45 seconds. This regulator is only a week old. Did I ruin it already or are these cheap?

So... did you follow the instructions?

Even though it says to ignore it - I am going to ask: what pressure does your right side gauge report?

I am running one of them for almost 10 years with zilch problems. Cheap needle valves might make your mileage vary a bit.

Mine only gets steady when I get the right gauge up to 40 then adjust the needle valve. Especially when hooked to a timer. Been using this regulator for about a year now... Its not consistent when kept on a timer or going off/on a lot. Sometimes it just stops and needs turned off/on real quick.

I understand that this can damage the needle valve over time so be careful, but I think that's something I can deal with to have a steady co2 supply.

This is a great thread, lots of information here on a good budget regulator. I recently got a brand new M957 for $60, but it came with a leaky solenoid, so I am planning on using it for a fishless tank system that will have 8 aquariums total hooked up to it. I too have had some problems adjusting the needle valve, its not that precise, but for the price it gets the job done. I wouldn't not suggest using this regulator on a tank with a bunch of expensive fish, but to have on hand as a backup or to use for fishless systems it would work amazingly.

This is a great thread, lots of information here on a good budget regulator. I recently got a brand new M957 for $60, but it came with a leaky solenoid, so I am planning on using it for a fishless tank system that will have 8 aquariums total hooked up to it. I too have had some problems adjusting the needle valve, its not that precise, but for the price it gets the job done. I wouldn't not suggest using this regulator on a tank with a bunch of expensive fish, but to have on hand as a backup or to use for fishless systems it would work amazingly.

Sounds like your doing what I am doing. I will be pulling my retired Milwaukee out and running it on (8) fishless tanks. I replaced mine with the electronic Aquariumplants.com regulator and it rocks. Until I can get another Aquariumplants regulator the Milwaukee will serve it purpose since it will only be aquascaped tanks for at least a year. I just hope it still works as it did before it was retired.

Glad I ran across this troubleshooting thread though. Only issue I actually had with this regulator as well as any with a solenoid I guess, is the dumping of the tank. I lost half my tank due to me missing my "time to refill" window. But I will definite use this thread if needed.

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